Hydraulically operable apparatus for making slit trenches

ABSTRACT

A hydraulically operable implement for producing in the ground vertical deep slit trenches of narrow width which comprises a gripping device adapted to be actuated by an extra long boom and a dipper arm, in which said gripping device suspended on the lower end of beam means through the intervention of a rotatable head connected to the free end of a dipper arm and supporting said beam means is braced relative to said implement by a bridge pivotally connected to a carriage on said implement, the free end of said bridge being provided with a cradle frame extending around said beam means.

United States Patent 1191 Heusler et al. 1 A r. W 1973 [54]HYDRAULICALLY OPERABLE [56] I References Cited APPARATUS FOR MAKING SLITUNITED STATES PATENTS TRENCHES 2,639,048 5/1953 Glashaw ..2l4/l38 [75]Inventors: Helmut Heusler, Dortmund- 2,788,143 4/1957 LaTendresse.....2l4/147 G Kirchhorde; Dieter Maly, Lobe, 3,143,229 8/1964 Billings.214] 147 G both Germany 3,462,029 8/1969 Mork 114/133 [73] Assignee:()renstein 8: Koppel Aktien- FOREIGN PATENTS OR APPLICATIONS gigg y1,952,116 5/1970 Germany ..l7S/238 [22] Filed: Jan. 22, 1971 PrimaryExaminer-Gerald M. Forlenza Assistant Examiner-Lawrence J. Oresky 1Appl' 108772 Attorney-Walter Becker Related US. Application Data 57 CT[63] Continuation-impart of Ser. No. 785,69l/Dec. 23,

1967, abandoned. A hydraulically operable implement for producing 1n theground vertical deep slit trenches of narrow width [30] ForeignApplication Priority Data which comprises a gripping device adapted tobe actu- 3 .ated by an extra long boom and a dipper arm, in Dec.23, 1967Germany ...P 16 4923.8 which Said g pp g device Suspended on the lower 1end of beam means through the intervention of a [52] US. Cl. 175/45,173/282, rotatable head connected to the free end of a dipper Int ClE21b/47/0'2 arm and supporting said beam means is braced rela- [58]Field of Search ..214/138, 147, 147 G; r Sad Implement by a bndge pvmanynnected to a carriage on said implement, the free end of said bridgebeing provided with a cradle frame extending around said beam means.

4 Claims, 9 Drawing Figures PATEHTEB APR 1 01975 SHEET 1 [IF 4 FIG-4PATENTED APR 1 0 I975 sum 2 OF 4 HYDRAULICALLY OPERABLE APPARATUS FORMAKING SLllT TRENCHES This is a continuation-in-part of copendingapplication Ser. No. 785,69lI-Ieusler et al. filed Dec. 20, 1968 nowabandoned and belonging to the assignee of the present invention.

The present invention relates to a hydraulically operable device fordigging slit trenches and, more specifically, concerns a device of theabove mentioned type which is hydraulically operated and produces deepvertical slit trenches of small width while a gripping device, forinstance a grab bucket, is actuated by means of an extra long boom andclipper arm.

According to a heretofore known device for digging such trenches, theboom of a dredge has connected thereto a vertically extending pipe whichcan be adjusted as to height. At the lower end of the pipe there arepivotally connected gripper bucket sections which are actuatedhydraulically. Furthermore, parallel to said pipe there are arrangedguiding means along which a rammer slides. Such a device is suitable fordeeper excavations but requires relatively large space for the freedomof movement of the gripper device. For digging small slit trenches, asthey are necessary when building tunnels for supporting the adjacentbuildings or houses, such device is not suitable.

According to another heretofore known device for digging deepexcavations, the boom of a dredge has connected thereto between saidboom and the dipper arm an additional intermediate part in order tomaster the necessary kinematics during the deeper lowering of thegripping device. This last mentioned device makes it possible to realizedeeper excavations than is customary with ordinary equipment. Theadditional actuation of said intermediate member by a hydraulic pistoncylinder system results in an expensive construction which can effectonly such excavations which do not have the relatively small dimensionsas they are necessary for supporting walls during the building oftunnels.

It is, therefore, an object of the present invention to provide ahydraulically operable device for digging slit trenches while using onlycustomary dredge equipment and'changing the kinematics thereto to aminimum extend and while the slit trench will have a minimum width.

The above object and other objects and advantages of the invention willappear more clearly from the following specification in connection withthe accompanying drawing, in which:

FIG. ll illustrates in side view an earth dredger with a gripping deviceshown outside the slit trench dug thereby.

' FIG. 2 is a side view of the device according to the invention withthe gripping device partially lowered between the walls of the slittrench.

FIG. 3 is a side view similar to that of FIG. 2 but with the grippingdevice lowered to the bottom of the slit trench.

FIG. 4 shows on a larger scale thanFIG. 1 the lower portion thereof withthe cradle frame.

FIG. 5 is a top view of FIG. 4. FIG. 6 shows an enlarged side view ofthe gripping device of FIG. 4 as seen in the direction ofthe arrow AFIG. 7 is a side view showing fastening of the connection rod to thegripper device stem.

FIG. 8'shows another embodiment of structure similar to that of FIG. 6based on FIG. 1 modified with rigid fastening of the gripper device on aconnection rod or beam.

The dredger according to the present invention is characterizedprimarily in that the gripping device is suspended on a beam which inits turn is carried by a rotatable head pivotally connected to the freeend of the dipper arm of the dredger. Furthermore, the said grippingdevice is braced against the dredger by means of a bridge which ispivotally connected to the upper carriage of the dredger, the free endof said bridge being provided with a cradle frame which surrounds thefree end of the connecting beam.

According to a further development of the present invention, the cradleframe is so mounted on the free end of the bridge that the cradle frameis journalled to carry out a pendulum movement with respect to the freeend of the bridge.

In view of the pivotal support of the gripping device on the dredger bymeans of the bridge, it will be assured that the gripping device isprevented from carrying out a pendulum movement during a pivotingoperation of the boom, even if it should be particularly long, and ofthe dipper arm so that the introduction of the gripping device duringthe excavation even of a narrow slit trench having a depth of up to 30meters will be effected in a precise manner. In order to assure a fastoperation of the gripping device, the actuation of the boom and 'of thedipper arm can be effected by the actuation thereof by means of apotentiometer system independently of the operator and in conformitywith the respective position of the gripping device.

For purposes of facilitating the operation, means may be provided whichenable the operator to ascertain the closing of the gripping device atthe bottom of the slit trench so that he can initiate the upward strokeof said gripping device.

Referring now to the drawings in detail, the upper carriage l of anearth dredger movable by a caterpillar track mechanism 2 has pivotallyconnected thereto a boom 4 which is operable by a hydraulic cylinderpiston system 3. Pivotally connected at 7 to the boom 4 is anextraordinarily long dipper arm 6 which at 7a is operatively connectedto a hydraulic cylinder piston system 5 for actuation of said dipper arm6. The free end 8 of said dipper arm 6 is pivotally connected to arotatable head 9 which in its turn carries a connecting beam 10, in thisparticular instance a lattice beam. Mounted on the connecting beam areguiding members 11 by means of which the connecting beam 10 during thelowering thereof is guided into the slit trench 13 defined by the walls12. In order to secure a certain distance of the dredger from the slittrench 13 to be dug, the upper carriage 1 has at the pivot 15 pivotallyconnected thereto a bridge 14. At a pivot 17 on the free end 18 of theconnecting beam 10, the cradle frame 16 may be so arranged that itsurrounds the gripping device 20 which is pivotally suspended at 19 onthe free end of the connecting beam 10. I

The operation of the dredger according to the present invention is asfollows. The operator drives the dredger toward the area where the slittrench is to be dug while spacing said dredger from said area inconformity with the length of the bridge 14. The boom 4 and the dipperarm 6 will occupy their highest also most vertical position, and thegripping device 20 will be directly above the slit trench to be dug. Ifnow the operator starts to lower the gripping device, the connectingbeam passes through the cradle frame (FIG. 2). When the gripping devicereaches the bottom 21 of the slit trench 13, the gripping device closesand a switch (not shown) actuated during the closing movement conveys acorresponding indication to the operator by means of a lamp which lightsup and is located in the operators cab.

FIG. 8 represents another embodiment of the attachment of the grippingdevice 20' at a lower end 18' of the connection rod 10; while theconcern with FIG. 6 is with a movable fastening by way of Cardan orgimbal ring linkage, according to FIG. 8 a rigid fastening of thegripping device 20' on the connection 10 is provided. For bothembodiments there exists that the holding means 20a respectively 20a and20b movably passes through the cradle frame 16 respectively 16. By wayof holding means or cams 18a, 18a secured at the lower end I8, 18 thereis taking along of the cradle frame 16, 16' during lifting of thegripping device, which means by way of actuation of the connection rod10. It becomes clear from FIG. representing a plan view how theconnection rod respectively the lower end 18, cams 18a, cradle frame andbridge 14 are arranged with respect to each other. Views of FIG. 5, FIG.6 and FIG. 8 include the foregoing reference numerals.

FIGS. 7, 7a and 8 show structure similar to that in the foregoingdescription and accordingly similar reference numerals are appliedthereto. FIG. 8 has primes'added to corresponding reference numerals.

FIG. 8 shows another embodiment of structure similar to that of FIG. 6based on FIG. 1 modified with rigid fastening of the gripper device on aconnection rod or beam.

It may be added that, when the operator starts to lower the grippingdevice, the sinking movement of the gripping device is preferablyautomatically controlled by an electrically programmed closing movement.Anybody skilled in the art of electrically programming control movementswill be able to lay out a corresponding control circuit which issuitable for this purpose in view of the operations to be carried out.

The upper carriage l of an earth excavator movable by a caterpillartrack mechanism 2 is pivotally connected by way of hydraulic cylinderpiston means 3 to a boom 4 operable thereby. An extraordinarily longdipper arm 6 to be actuated is pivotally connected at the turning pointor pivot 7 on the boom 4 by way of a hydraulic cylinder piston means 5.

At a free end 8 of the dipper arm 6 there is hung up a connection rod10, in this case a lattice work, grill or trellis, subject tointermediate connection of the turning or rotatable head 9. Guidingmembers 11 are mounted on the connecting rod or beam 10 by means ofwhich the connection rod or beam 10 can be guided during lowering intothe slit trench 13 formed by way of the slit walls 12. In order toattain a particular spacing of the excavator from the slit trench 13 tobe produced, there is a bridge 14 pivotally journalled in a turningpoint or pivot 15 on the upper carriage 1. Rather than at the free end18 of the connection rod or beam 10,

the cradle frame 16 can also be so secured that the same surrounds thegripping device 20 pivotally hung up in the turning or rotatable point19 on the free end 18 of the connection rod or beam 10.

The manner of operation is as follows: The excavator is driven by theoperator into a location or spacing from the slit trench 13 to beproduced by way of the length of the bridge determining such spacing.Thereby the boom 4 and the dipper arm 6 are found in the highest,approximately vertical positioning and the gripping device 20 is locateddirectly above the slit trench to be produced. If the operator nowbegins the lowering of the gripping device, there is thus controlled thesinking or deepening movement of the gripping device by way of theclosing movement with the aid of the length of the boom and dipper armcharacterized with respect to each other. Hereby the connection rod orbeam 10 glides or slides through the cradle frame 16 (FIG. 2). When thegripping device reaches the bottom 21 of the slit trench 13, thegripping device closes itself and a switch actuated during the closingmovement indicates this by way of a lamp illuminated in the excavatorguide stand or control platform 1a. The hydraulically actuated apparatusfor production of vertical, deep slit trenches with a narrow or nominalwidth in the ground whereby a gripping device is actuated by means of anextraordinarily long beam and dipper arm on the excavator can becharacterized thereby that a gripping device 20 is supported relative tothe excavator or dredger subject to intermediate connection by way of abridge 14 pivotally journalled on an upper carriage 1 of the dredgersubject to intermediate connection by way of a rotating head 9 on aconnection rod or beam 10 relative to a free end 8 of the dipper arm 6to which the rotating head 9 is secured; the bridge at its free end isprovided with a cradle frame 16 surrounding the free end of theconnection rod or beam 10. The gripping device 20 is surrounded by thecradle frame 16 journalled in the manner of a pendulum at the free endof the bridge 14. The gripping device is provided with an indicating endswitch actuating means to represent closure of the gripping device-beingcompleted upon the bottom of the trench and this switch means results inenergization of a lamp actuated in the excavator control stand orplateform-cab.

The rail or track guided special slit dredgers or excavators are usedpredominantly at large construction locations. The gripping basket issecured hereby on a positively guided beam or stem which exerts a highloading upon the gripping basket (around four tons). High excavatingcapability can be attained thereby also with tightly compacted ground.In addition, the closing and opening of the gripping device is achievedhydraulically. The removal of slit or trench walls previously occurredexclusively with rope or cable excavators which were equipped withspecial gripping means (slit wall grippers). The grippers, mostlyconstructed by building firms themselves have relatively long guidemeans. The journalling locations are well closed off or sealed. The sidewalls and the bottom of the gripper shells are provided with slits so.that liquid suspension can flow away. The width and depth of the slitwalls depend upon the purpose of utilization. At present in Germanymainly 600 millimeter and 800 millimeter widths and as far as 30 meterdepths are produced with respect to the slit walls. There is, however, atrend toward more narrow (400 millimeter) and wider (as far as over1,000 millimeter) slit walls to be established.

The manner of slit production, whether a continuing slit or individuallayers are excavated depends upon the local characteristics; forinstance, the type of grour'id, the height of the ground water, eventualloading along the slit by way of traffic or buildings. Mostly the slitis produced by individual layers, the length of which is at least aslarge as the opening width of the gripping means utilized and amountingto a maximum as far as over 6 meters.

One utilizes hereby two methods as follows:

1. Continually advancing toward both sides (layers l, 2,3,4,5 and soforth).

2. lntermittently advancing toward both sides (layers 1, 3, 5, 7 and soforth and then the intermediate layers 2, 4, 6 and so forth).

Upon start of the excavating work there is introduced or filled-in asuitable suspension, for instance, Botonit as far as to the height ofthe leading wall of which the hydrostatic pressure is to hinder thecollapse of the trench or slit. The suspension (thixotropic liquid) mustbe post-filled according to the particular excavation or removalcorresponding thereto. Pure suspension does not attack metallic workmaterials. The suspension contaminated during the excavation or removalleads to strong wear of the journalling locations. For this'reason, thejournalling locations on the gripping device must be well sealed andclosed off.

I The slit or trench walls are strengthened corresponding to the staticrequirements. Prior to the introduction of the strengthening, the slitor trench bottom is worked over and cleaned. The strengthening isprefabricated according to the layer lengths corresponding to theindividual baskets or containers and the same are installed with the aidof auto cranes or tower rotating crane means.

In order to attain the desired side profiles during the layering, oneutilizes, for example, semi-circular profile tube means which remain inthe slit or trench until after the concreting as a kind of lining. Oneor two pipes or tubes are needed according to the particular operatingtechnique selected for each layer and the outer diameter of the pipes ortubes equals the slit wall width.

If one selects the continually advancing slit excavation toward bothsides, then for the first layer one needs two tubes or pipes and foreach further layer only one additional tube or pipe would be needed.

With the second method, there are two tubes or pipes at a time necessaryin the layers 1, 3, and so forth while for the intermediate layers (2,4, 6 andso forth) no tubes are any more necessary or needed. After thecementing or concreting, the tubes or pipes are either pulled with acrane or with a hydraulic pulling apparatus (pulling strength l00-l20Mp).

The slit wall'manner of construction lately has been utilized morefrequently, for instance, with street car underpass'es, departmentstores, underground garages, high rise buildings, underground railroadconstruction and many others. The latter mannerof construction more andmore replaces the previously utilized methods (predominately largecities utilization thereof occurs). I r

The present invention concerns hydraulically operated apparatus forproducing vertical, deep slit trenches of narrow width in the groundwhereby a gripping device is actuated by an extra long boom and a dipperarm or stem.

In recent years, concrete walls have been produced more frequentlyinconstruction ground. This method generally has been known for severaldecades; production of narrow, elongated and unlined trench constructionor excavations is new herewith for receiving the concrete. Theseslit-formed construction trenches can remain unlined when afluid orliquid introduced during the excavating operation can bring aboutstanding capability of the walls. The slit manner of construction offersa series of advantages. Slits are utilized in those cases in which thetraffic must be maintained also during the construction operation. Theslits are produced with gripping devices in individual sections orsegments of which the length is at least as large as the opening widthof the gripping devices utilized which can amount to a maximum as far asover 6 years. With a known apparatus for excavating, there is avertically standing pipe or tube fastened to the boom of an excavatorand this pipe or tube can be adjusted according to the height. At thelower end of the tube, there are gripping shelves linked thereto whichare actuated hydraulically. Additionally, a guide means is providedparallel to the tube along which a ram bar glides or slides. Such anarrangement is suitable for deeper excavations, requires, however, spacefor the freedom of movement of the gripping means. Such an apparatus isnot suitable for producing narrower slit trenches as, for instance,during tunnel construction for support of adjoining property andbuildings as would be necessary for adjoining property and buildings.

With a further known apparatus for producing termediate part on the boomof an earth excavating means and a dipper arm in order to controlnecessary movement or kinematics of the gripping means during deeperlowering or use thereof. Hereby deeper excavations can be attained thanusual with normal equip- ,mcnt. The additional utilization of theintermediate piece by way of hydraulic cylinder means requires a complexdevice with which only excavations can be achieved which do not attainthe nominal measure ments necessary for instance for support wallsduring tunnel construction.

The basis of the present invention lies in being able to produce verydeep slit trenches with as small a width as possible with a usualexcavating equipment subject to the least possible change in themovements or kinematics and the parts involved. The solution of thisgoal occurs inventively thereby that subject'to intermediate connectionof a free end of the dipper arm a turning head is secured on aconnection rod having a gripping means hanging or pendulously supportedtherefrom by way of a pivotally joumalled bridge on the super structureor upper vehicle portion of the excavating means, the bridge at its freeend being provided with a cradled frame surrounding a free end of theconnection rod and being backed or supported with respect to theexcavator. The gripping device is joumalled surrounding the cradle framein a swinging manner at the free end of the bridge. Due to thearticulated support of the gripping device on the excavator by means ofthe bridge, there is achieved that the gripping device also does notswing or pendulate with extra long boom and dipper arm structure duringa pivotal movement and the application thereof during excavation canalso result in very narrow exact slits and as deep as from to meters.For facilitating operation, there can be provided an indicator by meansof which the operator can determine the closing of the gripping deviceat the bottom of the slit and the operator can then initiate the upwardstroke or movement of the device.

What we claim is:

1. A dredger for digging a slit trench of a narrow width, whichincludes: movable supporting means, an upper carriage rotatablysupported by said supporting means, a boom having one end portionpivotally con nected to said carriage, first fluid operable cylinderpiston means pivotally connected to said carriage and said boom forpivoting the latter, dipper arm means having one end portion thereofpivotally connected to the other end portion of said boom, second fluidoperable cylinder piston means pivotally connected to said boom betweenthe end portions thereof and also pivotally connected to one end portionof said dipper arm means for pivoting said dipper arm means about itspivotal connection with said boom, a head having the other end of saiddipper arm means pivotally connected thereto, beam means having one endportion supported by said rotatable head, a gripping device pivotallysupported by the other end portion of said beam means, bridge meanshaving one end portion pivotally connected to said upper carriage, and acradle frame supported by the other end portion of said bridge means andhaving said beam means shiftable reciprocably therein.

2. A dredger according to claim 1, in which said cradle frame isjournalled at the other end portion of said bridge means pivotallysuspending said gripping device in a manner similar to a swingingpendulum.

3. A dredger according to claim 2, in which said cradle frame surroundsaid end portion of said bridge means pivotally suspending said grippingdevice.

4. A dredger according to claim 3, in which a switch means is providedon said gripping device and closure thereof occurs with trenchbottoming, and an indicator lamp means energized by closure of saidswitch means as an operator control indicator.

1. A dredger for digging a slit trench of a narrow width, whichincludes: movable supporting means, an upper carriage rotatablysupported by said supporting means, a boom having one end portionpivotally connected to said carriage, first fluid operable cylinderpiston means pivotally connected to said carriage and said boom forpivoting the latter, dipper arm means having one end portion thereofpivotally connected to the other end portion of said boom, second fluidoperable cylinder piston means pivotally connected to said boom betweenthe end portions thereof and also pivotally connected to one end portionof said dipper arm means for pivoting said dipper arm means about itspivotal connection with said boom, a head having the other end of saiddipper arm means pivotally connected thereto, beam means having one endportion supported by said rotatable head, a gripping device pivotallysupported by the other end portion of said beam means, bridge meanshaving one end portion pivotally connected to said upper carriage, and acradle frame supported by the other end portion of said bridge means andhaving said beam means shiftable reciprocably therein.
 2. A dredgeraccording to claim 1, in which said cradle frame is journalled at theother end portion of said bridge means pivotally suspending saidgripping device in a manner similar to a swinging pendulum.
 3. A dredgeraccording to claim 2, in which said cradle frame surround said endportion of said bridge means pivotally suspending said gripping device.4. A dredger according to claim 3, in which a switch means is providedon said gripping device and closure thereof occurs with trenchbottoming, and an indicator laMp means energized by closure of saidswitch means as an operator control indicator.